Tri-Star Industries Ltd, located in Yarmouth, NS, builds ambulances and other vehicles that are used around the world. https://tri-star.ca/
There is also variety of ancillary vehicles, but the ones closest resembling regular ambulances are Patient Transfer Units. They do not have the same red lights, but the modular body is similar.
In the last few days I have seen a different ambulance, and this one is built on a Freightliner crew cab chassis with Tri-Star body. Numbered CC1, it is classed as a Critical Care Transport, but has been pressed into service with the LifeFlight helicopter service.
There are helicopter pads on the roofs of the IWK Health Centre (women's and children's hospital) and the Halifax Infirmary of the Queen Elizabeth II Health Centre (general hospital). However if weather conditions or other circumstances do not permit roof landings, there is a ground pad between Point Pleasant Park and the Halterm container terminal.
Since April 1, the current EHS LifeFlight Sikorsky helicopter has been forbidden from using the roof top pads due to lack of certification and it will have to be replaced. In the meantime (up to 9 months) it will be using the Point Pleasant pad.
The Critical Care Transport CC1 is being used as the shuttlke ambulance between the helo pad and the hospitals (a trip estimated by the press as 15 minutes - but I reckon to be closer to 10 or less)
Except for on board equipment and doors, Patient Transport Units are essentially the same as regular ambulances. Aside for the red lights on the ambulances, it is hard to tell them apart from a distance.
(PTU at left, 400 series Ambulance at right)